Ammonium-sulfate-recovery process.



J. BECKER. AMN'INIUM SULFATE RECOVERY PROCESS.

- Patented Jun. 2l, 1919.

@NITE STE@ PEN'I EEIC JOSEPH BECKER, 0F PITTSBURGH, PENNSYLVANIA, ASSIGNOR TO THE KOPPERS COM- PANY, OF PITTSBURGH, PENNSYLVANIA, A CORPORATION OF PENNSYLVANIA.

AMMONIUM-SULFATE-RECOVERY PROCESS.

Application led August 12, 1918.

To all whom it may concern Be it known that I, Josnrn BECKER, (assigner to H. Koppers Company, a corporation of Pennsylvanim) a subject ofGermany, who has declared his intention of becoming a citizen of the United States, and

is residing in Pittsburgh, in the county of Allegheny and State of Pennsylvania, have invented a new and useful Improvement in Ammonium-Sulfate-Recovery Processes, of which the following is a specification.

My invention relates primarily to the recovery of ammonia from coke-oven gas and has for an object the elicient combining of saturator and distillation processes with special economy of heat and simpliiicatiou of operation; and the invention may also be applicable to the treatment of gas that is otherwise derived from the carbonization of coal, and may also have such other objects and results as are found to obtain in the processes hereinafter set forth and claimed.

In the accompanying drawings, Figure 1 is a conventional diagram illustrating an embodiment of the invention in a preferred arrangement of apparatus for practising its processes; and Fig. 2 is a key to the symbols employed in the various lines that show the connections between the apparatus indicated in Fig. 1.

The coke-oven gas from the ovens first enters and passes through the primary coolel` The condensate from such cooler is drained into the tar and ammonia-liquor tank 6, from which the ammonia-liquor is v decanted into the ammonia-liquor tank 7.

The cooled gas is drawn from the primary cooler 5 through the exhauster 8 and then forwarded into and through the tar extractoi` 9 in which the residue of the tar is extracted, and from which the recovered tar flows into the aforesaid tank 6. The ammonia-liquor is drawn from the said ammonia-liquor tank 7 by the pump 10 and forwarded to the elevated ammonia-liquor tank '11, from whichit flows into the ammonia-still 12 to be there distilled by the heat from the steam supply 13. A portion of the cool gas from the tar-extractor 9 lows directly, through the pipe 14E, into the saturator 15, but a portion is conveyed through the by-'pass 16 to the .still 12 and `flows up through said still and issues thereyfrom with the still-vapors. Such still-.va-

pers ard gas issuing from the still pass first.

Specification of Letters Patent.

Patented Jan. 21, y1919.

Serial No. 249,380.

Vwarded through the vapor-line l5) that leads back to the aforesaid gas connection 1-1 entering the saturator. Such heated inflow. serves to heat the entire gas iniow into lthe saturator sufliciently to effect the evapo'ration required to precipitate the ammonium sulfate from the saturation-bath. The ammonia-freed gas passes from the saturator through the outlet gas-line 20. The dephlegmator 17 is supplied with cooling water circulating from its water inlet 21 to its water outlet 22. The condellsate from the dephlegmator 17 flows back into the still through the drain-line connection 23. The reheater is heated by steam supplied through the steam connection 24; and the steam from the reheater is led oit through the pipe 25 that terminates in an injector nozzle within the discharge end of the by-pass 1G, to force the gas from said by-pass into the still and to serve as a supplemental steam-supply -for the still, such steam-flow being adjusted by a valve in said pipe 25. The waste-drain from the still is indicated at 26.

The gas intermixed and heated with the still-vapors provides a suflicient volume to carry, with the still-vapors, the heat required to be introduced into the cool gas passing directly from the tar-extractor into the saturator, to save the reheating of the latter main volume of gas intermediate the tar-extractor and saturator, and substantial economy of heat is effected.

The processes of the invention may be practised in various ways, other than the particular embodiment that has been described for purposes of illustration, and still be within the scope and subject matter of the claims hereinafter made.

I claim:

1,. In a process for the recovery of arnmonium sulfate, the combination of steps that consists in z' cooling the ammoniacharged gas and draining off the condensate tar and ammonia-liquor; extracting the residue of tar from such cooled gas; distilling the lammonia-liquor; employing a portion of the cool tar-freed to augment the volume of the vapors in the discurrent of thev other portion of the cool tarfreed gus, to import heet to the lutter; and

passing the resultant super-heated mixture' of gus and still-rupors through e. satu ationlmth, to give up their ammonia in such hath and to eliect the deposition of nmmonium sulfate therein; snshtzintinlly :is specified.

Q. In :t process for the recovery of um Inonium. sulfate, the combination of steps that consists in: cooling the ammoniachurged gus and draining ot the condensate tur und unnnoniu-liquor; extracting the residue ot' tar from the cooled was; distilling the anniloniivliquor and depzlilegmnting und reheziting thc still-\'npoi's; passing e portion ol the cooled tur-freed gus into the current et the distillation7 to augment the volume ot' the still-vapors and derive heat ywith them in the distillation und reheuting operation; conducting` the' conlmingled vollune of superheuted still-vapors and gus into the current ot' the other portion of the cool tur-freed gas; to supcrhent thc lutter; und passing the resultant superheuted mixture ot ,qms :nul vapors into and through a seturution-bath, to effect absorption of their ammonia und deposition of ammonium sul tute; substantially as speciicd.

3. In a process for the recovery of ammonium sulfate, the combination of steps that consists in: distilling the condensate nnnnonizL-liquor from cooled and tar-freed neoryrso nnnnonia-chztrged gus; rebooting e portion of said ges in the distillation operation; and employing the connningled hot ges und stili: vapors to effect the snperheuting oit the other portion of thccool tor-treed so that entire volume of ges and vapors, in passing through e saturation-beth for the absorption ot' their ammonia; effect the evaporation req uisite to cause the deposition of ammonium sulfate in said bath; substantially as specified.

in n process for the recovery of ammonium sulfate; the coinbinzition of steps that consists in; tlistilling the condensate ammonia-liquor from cooled and ter-freed :unmoniwclmrgcd ges; reheating s. portion of said gos in the distillation operation; conducting the other portion of the, cooled gas into a saturation-beth; and employing the connningled rcheuted gas und still-vapors to effect, in passing through the seme suturution-both, the evaporation requisite to cause the deposition of ammonium sulfate in said bath; substantially as specied.

in testimony whereof, hereunto set my hand in the presence of two subscribing Wit nesses.

JOSEPH BECKER.

Witnesses HENRY LOVE omessa, Josemi Dvormn. 

